Human placental membrane (e.g. amniotic membrane or tissue) has been used for various types of reconstructive surgical procedures since the early 1900s. The membrane serves as a substrate material, more commonly referred to as a biological dressing or patch graft. Such a membrane has also been used widely for ophthalmic procedures. Typically, such membrane is either frozen or dried for preservation and storage until needed for surgery.
Such placental tissue is typically harvested after an elective Cesarean surgery. The placenta is composed of the umbilical cord and amniotic sac. The amniotic sac, commonly referred to as the amniotic membrane, has two primary layers of tissue, amnion and chorion. Amnion tissue is innermost layer of the amniotic sac and in direct contact with the amniotic fluid. The amniotic sac contains the amniotic fluid and protects the fetal environment. Histological evaluation indicates that the membrane layers of the amnion consist of single layer of epithelium cells, thin reticular fibers (basement membrane), a thick compact layer, and fibroblast layer. The fibrous layer of amnion (i.e., the basement membrane) contains collagen types IV, V, and VII, and cell-adhesion bio-active factors including fibronectin and laminins.
Amnion tissue provides unique grafting characteristics when used for surgical procedures, including providing a matrix for cellular migration/proliferation, providing a natural biological barrier, are non-immunogenic, and contains numerous bio-active molecules, which can be used as a membrane to assist in tissue regeneration and improved healing outcomes in numerous applications. The membrane has the capability to self-adhere or, in the alternative, is susceptible of being fixed in place using different techniques including fibrin glue or suturing. Such grafts, when properly prepared, can be stored at room temperature for extended periods of time, without need for refrigeration or freezing, until needed for a surgical procedure.
Known clinical procedures or applications for such amnion grafts include ocular reconstruction, burns, anti-adhesion applications, barrier membranes, and general wound care. Described herein are membranes utilizing amnion tissue as building blocks to build membranes well suited for use in a variety of application such as, for example, perioplastic surgery and other surgical applications involving human mucosa tissue. The grafts and methods described herein utilize these biological molecules to enhance the performance of the amniotic membrane.